Addition to [731644]: also use the lock when using the getaddrinfo
emulation (ie. when HAVE_GETADDRINFO isn't defined).
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index e7e3c47..4447f09 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -141,9 +141,9 @@
 #endif
 
 /* On systems on which getaddrinfo() is believed to not be thread-safe,
-   protect access with a lock. */
+   (this includes the getaddrinfo emulation) protect access with a lock. */
 #if defined(__APPLE__) || defined(__FreeBSD__) || defined(__OpenBSD__) || \
-    defined(__NetBSD__)
+    defined(__NetBSD__) || !defined(HAVE_GETADDRINFO)
 #define USE_GETADDRINFO_LOCK
 #endif